In the past decade, 3D reflection seismology has replaced 2D seismology almost entirely in the seismic industry. Recording 3D surveys has become the norm instead of the exception. The application of 2D seismology is limited mostly to reconnaissance surveys or to locations where recording 3D data is still prohibitively expensive, such as in rough mountains and wild forests. However, academic research and teaching have struggled to keep up with the 3D revolution. As a consequence of this tardiness, no books are available that introduce the theory of seismic imaging from the 3D perspective. This book is aimed at filling the gap.

В настоящем сборнике содержатся тезисы докладов 1У регионального петрографического совещания по изучению магматических и метаморфических образований и по совершенствованию их изучения при крупномасштабном геологическом картировании.

Исполнилось 40 лет со дня установления Советской власти в Армении. 29 ноября 1920 г. трудовой армянский народ с помощью великого русского народа взял власть в свои руки. Над древней армянской землей взвилось победное знамя Октября.

The orebodies at the Getchell and Twin Creeks mines were studied through mineral paragenesis, geologic relationships, and 40Ar/39Ar dating. Mineral paragenetic relationships are based on observations made during the logging of 18,000 m of drill cuttings and core and crosscutting relationships recognized in the field and Main pit at the Getchell mine. Ages for igneous and mineralizing events were determined through 40Ar/39Ar incremental heating analyses of 15 samples of biotite, K feldspar, sericite, and vein adularia. A thermal history for the area was also developed using K feldspar multiple diffusion domain results and age determinations on cogenetic minerals, which have different argon closure temperatures.